6 results on '"St Leger JA"'
Search Results
2. Intestinal polycyclic aromatic hydrocarbon-DNA adducts in a population of beluga whales with high levels of gastrointestinal cancers.
- Author
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Poirier MC, Lair S, Michaud R, Hernández-Ramon EE, Divi KV, Dwyer JE, Ester CD, Si NN, Ali M, Loseto LL, Raverty SA, St Leger JA, Van Bonn WG, Colegrove K, Burek-Huntington KA, Suydam R, Stimmelmayr R, Wise JP, Wise SS, Beauchamp G, and Martineau D
- Subjects
- Animals, Arctic Regions, Beluga Whale, Fibroblasts drug effects, Fibroblasts pathology, Intestinal Mucosa cytology, Mice, Water Pollutants, Chemical toxicity, Carcinogenesis chemically induced, DNA Adducts toxicity, DNA Damage drug effects, Epithelial Cells pathology, Gastrointestinal Neoplasms etiology, Gastrointestinal Neoplasms pathology, Intestinal Mucosa pathology, Polycyclic Aromatic Hydrocarbons toxicity
- Abstract
Carcinogenic polycyclic aromatic hydrocarbons (PAHs) were disposed directly into the Saguenay River of the St. Lawrence Estuary (SLE) by local aluminum smelters (Quebec, Canada) for 50 years (1926-1976). PAHs in the river sediments are likely etiologically related to gastrointestinal epithelial cancers observed in 7% of 156 mature (>19-year old) adult beluga found dead along the shorelines. Because DNA adduct formation provides a critical link between exposure and cancer induction, and because PAH-DNA adducts are chemically stable, we hypothesized that SLE beluga intestine would contain PAH-DNA adducts. Using an antiserum specific for DNA modified with several carcinogenic PAHs, we stained sections of paraffin-embedded intestine from 51 SLE beluga (0-63 years), 4 Cook Inlet (CI) Alaska beluga (0-26 years), and 20 beluga (0-46 years) living in Arctic areas (Eastern Beaufort Sea, Eastern Chukchi Sea, Point Lay Alaska) and aquaria, all with low PAH contamination. Stained sections showed nuclear light-to-dark pink color indicating the presence of PAH-DNA adducts concentrated in intestinal crypt epithelial lining cells. Scoring of whole tissue sections revealed higher values for the 51 SLE beluga, compared with the 20 Arctic and aquarium beluga (P = 0.003). The H-scoring system, applied to coded individual photomicrographs, confirmed that SLE beluga and CI beluga had levels of intestinal PAH-DNA adducts significantly higher than Arctic and aquarium beluga (P = 0.003 and 0.02, respectively). Furthermore, high levels of intestinal PAH-DNA adducts in four SLE beluga with gastrointestinal cancers, considered as a group, support a link of causality between PAH exposure and intestinal cancer in SLE beluga. Environ. Mol. Mutagen. 60:29-41, 2019. Published 2018. This article is a U.S. Government work and is in the public domain in the USA., (Published 2018. This article is a U.S. Government work and is in the public domain in the USA.)
- Published
- 2019
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3. Pathology and causes of death in stranded humpback whales (Megaptera novaeangliae) from Brazil.
- Author
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Groch KR, Díaz-Delgado J, Marcondes MCC, Colosio AC, Santos-Neto EB, Carvalho VL, Boos GS, Oliveira de Meirelles AC, Ramos HGDC, Guimarães JP, Borges JCG, Vergara-Parente JE, St Leger JA, Fernández A, and Catão-Dias JL
- Subjects
- Animals, Bone Diseases mortality, Bone Diseases pathology, Brazil, Communicable Diseases mortality, Communicable Diseases pathology, Respiratory Insufficiency mortality, Respiratory Insufficiency pathology, Bone Diseases veterinary, Cause of Death, Communicable Diseases veterinary, Humpback Whale abnormalities, Respiratory Insufficiency veterinary
- Abstract
This study describes the pathologic findings of 24 humpback whales (Megaptera novaeangliae) found stranded along the Brazilian coast from 2004 to 2016. Eighteen (75%) animals evaluated were found stranded alive. From these, 13 died naturally on shore and five were euthanized. Six died at sea and were washed ashore. Of the 24, 19 (79.2%) were calves, four (16.7%) were juveniles, and one (4.2%) was an adult. The most probable cause of stranding and/or death (CSD) was determined in 23/24 (95.8%) individuals. In calves, CSD included neonatal respiratory distress (13/19; 68.4%), infectious disease (septicemia, omphaloarteritis and urachocystitis; 3/19; 15.8%), trauma of unknown origin (2/19; 10.5%), and vehicular trauma (vessel strike; 1/19; 5.3%). In juveniles and adult individuals, CSD was: emaciation (2/5; 40%), sunlight-thermal burn shock (1/5; 20%); and discospondylitis (1/5; 20%). In one juvenile, the CSD was undetermined (1/5; 20%). This study integrates novel findings and published case reports to delineate the pathology of a South-western Atlantic population of humpback whales. This foundation will aid in the assessment of the population health and establish a baseline for development of conservation policies.
- Published
- 2018
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4. Cutaneous Granulomas in Dolphins Caused by Novel Uncultivated Paracoccidioides brasiliensis.
- Author
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Vilela R, Bossart GD, St Leger JA, Dalton LM, Reif JS, Schaefer AM, McCarthy PJ, Fair PA, and Mendoza L
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- Animal Diseases pathology, Animals, Base Sequence, Biopsy, DNA, Fungal, Phylogeny, Animal Diseases microbiology, Dermatomycoses veterinary, Dolphins, Granuloma veterinary, Paracoccidioides classification, Paracoccidioides genetics, Paracoccidioides isolation & purification, Paracoccidioidomycosis veterinary
- Abstract
Cutaneous granulomas in dolphins were believed to be caused by Lacazia loboi, which also causes a similar disease in humans. This hypothesis was recently challenged by reports that fungal DNA sequences from dolphins grouped this pathogen with Paracoccidioides brasiliensis. We conducted phylogenetic analysis of fungi from 6 bottlenose dolphins (Tursiops truncatus) with cutaneous granulomas and chains of yeast cells in infected tissues. Kex gene sequences of P. brasiliensis from dolphins showed 100% homology with sequences from cultivated P. brasiliensis, 73% with those of L. loboi, and 93% with those of P. lutzii. Parsimony analysis placed DNA sequences from dolphins within a cluster with human P. brasiliensis strains. This cluster was the sister taxon to P. lutzii and L. loboi. Our molecular data support previous findings and suggest that a novel uncultivated strain of P. brasiliensis restricted to cutaneous lesions in dolphins is probably the cause of lacaziosis/lobomycosis, herein referred to as paracoccidioidomycosis ceti.
- Published
- 2016
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5. CIRCULATING CONCENTRATIONS OF THYROID HORMONE IN BELUGA WHALES (DELPHINAPTERUS LEUCAS): INFLUENCE OF AGE, SEX, AND SEASON.
- Author
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Flower JE, Allender MC, Giovanelli RP, Summers SD, Spoon TR, St Leger JA, Goertz CE, Dunn JL, Romano TA, Hobbs RC, and Tuttle AD
- Subjects
- Animals, Animals, Wild, Animals, Zoo, Female, Male, Aging blood, Beluga Whale blood, Seasons, Thyroxine blood, Triiodothyronine blood
- Abstract
Thyroid hormones play a critical physiologic role in regulating protein synthesis, growth, and metabolism. To date, because no published compilation of baseline values for thyroid hormones in beluga whales (Delphinapterus leucas) exists, assessment of thyroid hormone concentrations in this species has been underused in clinical settings. The purpose of this study was to document the concentrations of total thyroxine (tT4) and total triiodothyronine (tT3) in healthy aquarium-maintained and free-ranging beluga whales and to determine the influence of age, sex, and season on the thyroid hormone concentrations. Archived serum samples were collected from healthy aquarium-maintained (n=43) and free-ranging (n=39) belugas, and serum tT4 and tT3 were measured using chemiluminescence immunoassay. The mean tT4 concentration in aquarium-maintained belugas was 5.67±1.43 μg/dl and the mean tT3 concentration was 70.72±2.37 ng/dl. Sex comparisons showed that aquarium-maintained males had significantly greater tT4 and tT3 (9.70±4.48 μg/dl and 92.65±30.55 ng/dl, respectively) than females (7.18±2.82 μg/dl and 77.95±20.37 ng/dl) (P=0.004 and P=0.013). Age comparisons showed that aquarium-maintained whales aged 1-5 yr had the highest concentrations of tT4 and tT3 (8.17±0.17 μg/dl and 105.46±1.98 ng/dl, respectively) (P=0.002 and P<0.001). tT4 concentrations differed significantly between seasons, with concentrations in winter (4.59±1.09 μg/dl) being significantly decreased compared with spring (P=0.009), summer (P<0.0001), and fall (P<0.0001) concentrations. There was a significant difference in tT4 and tT3 concentrations between aquarium-maintained whales (5.67±1.43 μg/dl and 70.72±15.57 ng/dl, respectively) and free-ranging whales (11.71±3.36 μg/dl and 103.38±26.45 ng/dl) (P<0.0001 and P<0.001). Clinicians should consider biologic and environmental influences (age, sex, and season) for a more accurate interpretation of thyroid hormone concentrations in belugas. The findings of this study provide a baseline for thyroid health monitoring and comprehensive health assessments in both aquarium-maintained and free-ranging beluga whales.
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- 2015
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6. Discovery of a Novel Hepatovirus (Phopivirus of Seals) Related to Human Hepatitis A Virus.
- Author
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Anthony SJ, St Leger JA, Liang E, Hicks AL, Sanchez-Leon MD, Jain K, Lefkowitch JH, Navarrete-Macias I, Knowles N, Goldstein T, Pugliares K, Ip HS, Rowles T, and Lipkin WI
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- Animals, Codon, Genome, Viral, Genotype, Hepatitis A Virus, Human genetics, Hepatovirus physiology, High-Throughput Nucleotide Sequencing, Humans, Liver virology, Lung virology, RNA, Viral genetics, Real-Time Polymerase Chain Reaction, Spleen virology, Virus Replication, Hepatovirus genetics, Hepatovirus isolation & purification, Phylogeny, Seals, Earless virology
- Abstract
Unlabelled: Describing the viral diversity of wildlife can provide interesting and useful insights into the natural history of established human pathogens. In this study, we describe a previously unknown picornavirus in harbor seals (tentatively named phopivirus) that is related to human hepatitis A virus (HAV). We show that phopivirus shares several genetic and phenotypic characteristics with HAV, including phylogenetic relatedness across the genome, a specific and seemingly quiescent tropism for hepatocytes, structural conservation in a key functional region of the type III internal ribosomal entry site (IRES), and a codon usage bias consistent with that of HAV., Importance: Hepatitis A virus (HAV) is an important viral hepatitis in humans because of the substantial number of cases each year in regions with low socioeconomic status. The origin of HAV is unknown, and no nonprimate HAV-like viruses have been described. Here, we describe the discovery of an HAV-like virus in seals. This finding suggests that the diversity and evolutionary history of these viruses might be far greater than previously thought and may provide insight into the origin and pathogenicity of HAV., (Copyright © 2015 Anthony et al.)
- Published
- 2015
- Full Text
- View/download PDF
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